Release 3.1.0

[WIP] use vcpkg for getopt; build windows shared lib enhancements (#350)

* fix MSVC compiler shared library issues - mostly around 'extern const'

* add vcpkg install getopt to appveyor-windows.yml

show appveyor where to get getopt from vcpkg (non-static lib to avoid LGPL violation)

* add missing else case in lsquic_shared_support.h for windows static lib path

* have cmake spit out it's version

have cmake copy dependent dlls to build dir for tests on windows (getopt.dll)

* copy getopt.dll dep for tests

added commented version that requires >= 3.21 but handles any dll deps

* try caching boringssl dir to reduce CI build time since it's always same commit specified in config file

define VCPKG_ROOT in env since I can't seem to find it by VCPKG_ROOT or VCPKG_INSTALLED_DIR in appveyor's cmake v3.16 + vcpkg

* make windows cache dependent on yml and cmd

* sync up with changes to ls-qpack

Release 3.0.0

Release 2.27.1

- [API] New knob to set outgoing packet batch size.
- Aborted connection now become tickable immediately.
- Abort connection when HTTP/3 frame cannot be opened (can only happen
when malloc fails).

Release 2.24.0

- [FEATURE] QUIC and HTTP/3 Internet Draft 31 support. Drop ID-30
and ID-31 support.
- [BUGFIX] Divide-by-zero in newly enabled conn stats code when no
packets were sent.
- [BUGFIX] Memory leak in gQUIC client when server hello cannot be
parsed.
- [BUGFIX] Server Initial packet size calculation.
- Log user-agent and CONN_CLOSE reason when peer reports error.
- Example programs: Specify ALPN for echo and md5 clients and servers
(issue #184).
- Example programs: Don't add "QUIC_" prefix to lines in keylog file
(issue #185).
- http_server: Fix fd leak in preadv mode; fix preadv() usage when
reading from disk.

Release 2.20.0

- [FEATURE] QUIC and HTTP/3 Internet Draft 30 support.
- [FEATURE] Unreliable Datagram Extension support.
- [FEATURE] Adaptive congestion controller.
- [BUGFIX] Do not send MAX_STREAM_DATA frames on crypto streams.
- [BUGFIX] Fail with CRYPTO_BUFFER_EXCEEDED when too much CRYPTO
data comes in.
- [BUFFIX] Spin bit is now strictly per path; value is reset on
DCID change.
- [BUGFIX] Check that max value of max_streams_uni and
max_streams_bidi TPs is 2^60.
- [BUGFIX] Close IETF mini conn immediately if crypto session
cannot be initialized.
- Deprecate ID-28 (no browser uses it): it's no longer in the
default versions list.
- New programs duck_server and duck_client that implement the
experimental siduck-00 protocol. They quack!
- IETF crypto streams: don't limit ourselves from sending.
- Command-line programs: turn off QL loss bits if -G is used, as
Wireshark cannot decrypt QUIC packets when this extension is used.
- Turn all h3 framing unit tests back on.
- Fix malo initialization when compiled in no-pool mode.

Release 2.19.9

- [FEATURE] Add lsquic_stream_pwritev(). This function allows one to
reduce the number of system calls required to read a file from disk
by using lsquic_stream_pwritev() together with preadv(2).
- [BUGFIX] When stream is reset, it is writeable -- let user collect
the error.
- [BUGFIX] Calculate correct conn flow control if reading ends early.
- [BUGFIX] Remove stream from read and write queues on internal
shutdown. This is a regression introduced in 2.19.7.
- [BUGFIX] Swapped arguments in IETF RESET_FRAME generation.
- Turn off mini conn history when compiling with Visual Studio; this
allows the project to compile on Windows again.
- http_client: Add -3 flag to stop reading from streams early; code
cleanup.
- Don't use -Werror.

Release 2.19.8

- [FEATURE] Update the timestamp extension to latest version.
- [FEATURE] Cope with appearance of ECN blackholes.
- [OPTIMIZATION] return packno offset and size when header is generated.
- [BUGFIX] ignore old ACK frames in mini conns.
- [BUGFIX] Mark initial server path as initialized.
- [BUGFIX] Do not merge ACK if ECN counts do not match.
- Turn incoming packet number history in mini conn back on.
- Record mini conn event history again when compiled in debug mode.
- IETF mini conn: log when ACK is queued.
- Clean up and refactor code in several places.

Release 2.19.4

- [BUGFIX] Do not return an oversize MTU probe to connection twice.
- [FEATURE] Delayed Acks updated to latest draft. Still experimental.
- Minor code cleanup in IETF full connection.

Release 2.19.0

- [FEATURE] DPLPMTUD support. IETF connections now search for the
maximum packet size, improving throughput.
- [DEBUG] Record event in stream history when on_close() is called
in dtor.

Release 2.13.0

- [API] Use lsxpack_header structure to process incoming headers.
- [BUGFIX] Fix assertion when zero-padding Initial packet.
- [BUGFIX] Use idle timeout before we learn of peer's value.
- Use ls-hpack 2.0.0 -- has lsxpack_header changes.
- Use ls-qpack 0.14.0 -- new, common with ls-hpack, XXH seed (not used yet).
- Code cleanup: prefix exported functions with "lsquic_".

Release 2.12.0

- [FEATURE] QUIC timestamps extension.
- [API] New: ea_alpn that is used when not in HTTP mode.
- [BUGFIX] SNI is mandatory only for HTTP/3 and gQUIC.
- [BUGFIX] Benign double-free -- issue #110.
- [BUGFIX] Printing of transport parameters.

Release 2.11.0

- [FEATURE] QUIC and HTTP/3 Internet Draft 27 support.
- [FEATURE] Add experimental delayed ACKs extension.
- Drop support for Internet Draft 24.
- Code cleanup.

Add experimental support for delayed ACKs extension

Release 2.10.0

- [FEATURE] QUIC and HTTP/3 Internet Draft 25 support.
- [API] Drop support for ID-23.
- [BUGFIX] Set key phase bit on outgoing packets correctly.
- Code cleanup.

Release 2.9.0

- [API] Drop support for Q039.
- Improve ACK-queuing logic. Send an ACK once in a while if
peer keeps on sending non-ack-eliciting packets.
- Improve Alt-Svc string: Q050 and later are not included in
the old-style "quic" string.
- Send stateless resets if connection could not be promoted.
- Schedule MAX_DATA if needed when DATA_BLOCKED is received.
- Use ls-qpack 0.11.2 -- needed for server push optimization.
- Code cleanup: handle some error cases, improve logging.

Release 2.8.7

- [BUGFIX] Initial packet size check for IETF mini conn applies to
UDP payload, not QUIC packet.
- Support old and new school loss_bits transport parameter.
- Use Q run length of 64 as suggested in the loss bits Draft.
- Undo square wave count when packet is delayed.
- Code cleanup; minor fixes.

Release 2.8.1

- [FEATURE] Use occasional packet number gaps to detect optimistic
ACK attacks.
- [BUGFIX] Q050 client: all packet numbers are in the App PNS.
- [OPTIMIZATION] Merge multi-range ACK frames, not just single-range
ACK frames.
- IETF QUIC: use RTT estimate in ack timeout calculation.
- IETF handshake: abort conn when unexpected errors occur.
- Use PING rather than MAX_DATA frames to elicit ACKs from peer.
- Server: enforce 1200 byte Initial minimum packet size.
- [CLEANUP] Remove code to disable gQUIC crypto.
- [CLEANUP] Remove n_timestamps from ACK info struct.
- Optimize driver: reuse previous ancillary message when possible.

Release 2.8.0

- [FEATURE] Add support for Q050.
- [OPTIMIZATION] Reduce mallocs in gQUIC handshake.
- [BUGFIX] Disable redo of failed STREAM frame insertion with debug
logging.

Release 2.6.0

- [FEATURE] QUIC and HTTP/3 Internet Draft 24 support

Release 2.2.0: server included, ID-22 supported (#76)

Release 1.20.0

[FEATURE] Add support for Q046.

Release 1.18.0

- [API Change] Can specify clock granularity in engine settings.
- [BUGFIX] Pacer uses fixed clock granularity. Since the change on
2018-04-09, it is not necessary to try to approximate the next tick
time in the pacer: it can use fix clock granularity specified by
the user.
- [BUGFIX] Do not tick constantly before handshake is done.
- [BUGFIX] Do not exit tick prematurely: reuse packet with ACK. Even
if we cannot allocate *more* packets, we could still be able to write
to one already allocated.
- [BUGFIX] Do not schedule pacer if there are no lost packets.

Release 1.17.11

Fix strict aliasing warning in when compiling with optimizations

Release 1.14.0

- [API Change] Disable packet sending if full batch cannot be sent
If lsquic_packets_out_f() cannot send the whole batch, disable
packet sending until lsquic_engine_send_unsent_packets() is called.
- [BUGFIX] Handle case when STREAM frame does not fit.
- [BUGFIX] Always allow incoming STREAM frames to overlap. Peers
may send overlapping STREAM frames even if using versions older
than Q043.
- Custom header set fixes:
- set "FIN reached" flag when custom header with FIN flag is
claimed;
- do not return custom header set for a reset stream.

1.11.0: [FEATURE] Add support for Q044

Drop a defunct parsing method

Drop the few remaining references to Q041

Drop support for Q041

Drop support for versions Q037, Q038, and Q042

[FEATURE] Add support for Q043

[FEATURE] Add support for Q042

Update copyright year; add CONTRIBUTORS.txt

Replace some erroneously removed debugging code

More Windows Updates

Latest changes

- [OPTIMIZATION] Merge series of ACKs if possible

Parsed single-range ACK frames (that is the majority of frames) are
saved in the connection and their processing is deferred until the
connection is ticked. If several ACKs come in a series between
adjacent ticks, we check whether the latest ACK is a strict superset
of the saved ACK. If it is, the older ACK is not processed.

If ACK frames can be merged, they are merged and only one of them is
either processed or saved.

- [OPTIMIZATION] Speed up ACK verification by simplifying send history.

Never generate a gap in the sent packet number sequence. This reduces
the send history to a single number instead of potentially a series of
packet ranges and thereby speeds up ACK verification.

By default, detecting a gap in the send history is not fatal: only a
single warning is generated per connection. The connection can continue
to operate even if the ACK verification code is not able to detect some
inconsistencies.

- [OPTIMIZATION] Rearrange the lsquic_send_ctl struct

The first part of struct lsquic_send_ctl now consists of members that
are used in lsquic_send_ctl_got_ack() (in the absense of packet loss,
which is the normal case). To speed up reads and writes, we no longer
try to save space by using 8- and 16-bit integers. Use regular integer
width for everything.

- [OPTIMIZATION] Cache size of sent packet.

- [OPTIMIZATION] Keep track of the largest ACKed in packet_out

Instead of parsing our own ACK frames when packet has been acked,
use the value saved in the packet_out structure when the ACK frame
was generated.

- [OPTIMIZATION] Take RTT sampling conditional out of ACK loop

- [OPTIMIZATION] ACK processing: only call clock_gettime() if needed

- [OPTIMIZATION] Several code-level optimizations to ACK processing.

- Fix: http_client: fix -I flag; switch assert() to abort()

Latest changes

- [API Change] lsquic_engine_connect() returns pointer to the connection
object.
- [API Change] Add lsquic_conn_get_engine() to get engine object from
connection object.
- [API Change] Add lsquic_conn_status() to query connection status.
- [API Change] Add add lsquic_conn_set_ctx().
- [API Change] Add new timestamp format, e.g. 2017-03-21 13:43:46.671345
- [OPTIMIZATION] Process handshake STREAM frames as soon as packet
arrives.
- [OPTIMIZATION] Do not compile expensive send controller sanity check
by default.
- [OPTIMIZATION] Add fast path to gquic_be_gen_reg_pkt_header.
- [OPTIMIZATION] Only make squeeze function call if necessary.
- [OPTIMIZATION] Speed up Q039 ACK frame parsing.
- [OPTIMIZATION] Fit most used elements of packet_out into first 64 bytes.
- [OPTIMIZATION] Keep track of scheduled bytes instead of calculating.
- [OPTIMIZATION] Prefetch next unacked packet when processing ACK.
- [OPTIMIZATION] Leverage fact that ACK ranges and unacked list are.
ordered.
- [OPTIMIZATION] Reduce function pointer use for STREAM frame generation
- Fix: reset incoming streams that arrive after we send GOAWAY.
- Fix: delay client on_new_conn() call until connection is fully set up.
- Fixes to buffered packets logic: splitting, STREAM frame elision.
- Fix: do not dispatch on_write callback if no packets are available.
- Fix WINDOW_UPDATE send and resend logic.
- Fix STREAM frame extension code.
- Fix: Drop unflushed data when stream is reset.
- Switch to tracking CWND using bytes rather than packets.
- Fix TCP friendly adjustment in cubic.
- Fix: do not generate invalid STOP_WAITING frames during high packet
loss.
- Pacer fixes.

Latest changes

- [API Change] Sendfile-like functionality is gone. The stream no
longer opens files and deals with file descriptors. (Among other
things, this makes the code more portable.) Three writing functions
are provided:

lsquic_stream_write
lsquic_stream_writev
lsquic_stream_writef (NEW)

lsquic_stream_writef() is given an abstract reader that has function
pointers for size() and read() functions which the user can implement.
This is the most flexible way. lsquic_stream_write() and
lsquic_stream_writev() are now both implemented as wrappers around
lsquic_stream_writef().

- [OPTIMIZATION] When writing to stream, be it within or without the
on_write() callback, place data directly into packet buffer,
bypassing auxiliary data structures. This reduces amount of memory
required, for the amount of data that can be written is limited
by the congestion window.

To support writes outside the on_write() callback, we keep N
outgoing packet buffers per connection which can be written to
by any stream. One half of these are reserved for the highest
priority stream(s), the other half for all other streams. This way,
low-priority streams cannot write instead of high-priority streams
and, on the other hand, low-priority streams get a chance to send
their packets out.

The algorithm is as follows:

- When user writes to stream outside of the callback:
- If this is the highest priority stream, place it onto the
reserved N/2 queue or fail.
(The actual size of this queue is dynamic -- MAX(N/2, CWND) --
rather than N/2, allowing high-priority streams to write as
much as can be sent.)
- If the stream is not the highest priority, try to place the
data onto the reserved N/2 queue or fail.
- When tick occurs *and* more packets can be scheduled:
- Transfer packets from the high N/2 queue to the scheduled
queue.
- If more scheduling is allowed:
- Call on_write callbacks for highest-priority streams,
placing resulting packets directly onto the scheduled queue.
- If more scheduling is allowed:
- Transfer packets from the low N/2 queue to the scheduled
queue.
- If more scheduling is allowed:
- Call on_write callbacks for non-highest-priority streams,
placing resulting packets directly onto the scheduled queue

The number N is currently 20, but it could be varied based on
resource usage.

- If stream is created due to incoming headers, make headers readable
from on_new.

- Outgoing packets are no longer marked non-writeable to prevent placing
more than one STREAM frame from the same stream into a single packet.
This property is maintained via code flow and an explicit check.
Packets for stream data are allocated using a special function.

- STREAM frame elision is cheaper, as we only perform it if a reset
stream has outgoing packets referencing it.

- lsquic_packet_out_t is smaller, as stream_rec elements are now
inside a union.

Latest changes

- Add support for Q041; drop support for Q040

LSQUIC Client: Initial release